In article <5f7f4f$di3@nntpb.cb.lucent.com>, rma@clockwise.mh.att.com says...
>In article <5f7c46$ks2@ccshst05.cs.uoguelph.ca>,
>Kevin Mackenzie wrote:

>>Since there has been some talk of mirror lenses lately I have been
>>wondering if there is a mirror lens comparison anywhere on the net. I am
>>considering a mirror lens for an EOS camera so it has to be third party.
>>I have heard that the Nikon 500/8 mirror is a decent lens. I know that
>>Tamron and Tokina make 500/8 mirrors and Sigma makes a 600/8 mirror.
>>There are also a handful of other mirror lenses available. If no one
>>knows of any lens test sites then please tell us about your personal
>>experience. There seems to be a lot more opinion about mirror lenses than
>>actual experience.

>This really isn't a nature photography question and should really be
>posted to rec.photo.equipment.35mm. I've directed followups there.
>
>I've tried a few mirror lenses and none of them were great. I currently
>have the Tamron 500/8, which is decent if your expectations are not
>too high. Like *ALL* mirror lenses, it's not as good as a decent
>refractive lens. I have never seen any mirror lens test that suggested
>otherwise. Lepp did a test of the Nikon 500/8 mirror and it was about
>the same (or not quite as good as) the Sigma 400/5.6 APO. I think it tested
>slightly better than the Sigma 500/7.2 APO. [Note the Sigma 500/7.2 doesn't
>qualify as a decent refractive lens!]
>
>Be aware you will get no focus indication with a manual mirror lens
>on an EOS body (except for the image on the screen). Your choice may
>be very limited - either a T-mount lens (which rules out the decent
>3rd party lenses and leaves you with Kalimar and their like), or
>the Tamron lens - IF you can find a Tamron EOS mount adaptor (which
>I understand are very hard to find these days). I think the Sigma
>lens (600/8) may be available in an EOS mount too.

Was G. Lepp's test of the newer (compact, macro) 500mm f8 Nikkor, or the
older version? (I find the older version sharper than the newer, and well
ahead of the Tamron 500mm f8 and the Sigma APO 400mm f5.6 lenses.) It
is even good enough to be sharp on the TC14/14B converter (though it is
VERY slow - but using the converter also reduces the "hot-spot" effect).
I have gotten sharp, full-bleed 8 1/2" x 11 1/2" color magazine covers
with the older Nikkor 500mm f8 - it really is pretty good (roughly
equal in image quality to the Nikkor 300mm f2.8 and 400mm f3.5 used
wide-open - not bad!;-).
Hope This Helps